My wife and I are self employed people who relocated here from Nevada in 2002. We feel very comfortable in our 1885 Victorian home and enjoy the beauty and history of this small community. Like the original poster, the local economy does not impact our daily lives, as our business is internet related and is not dependant on one particular community or economy.
I suppose I would consider myself somewhat spoiled, coming from Las Vegas where businesses live or die by customer service, or lack thereof. I would say the most difficult thing to get use to is the lack of customer service in Marion, SC. It's not something that comes naturally for the average first level employees, whether that be at McDonald's, Food Lion (Grocery store) or the brand new Walmart.
Simple "Thank you's" are starkly missing. I feel its because courtesy from one segment of the poplulation is not instilled in them as children, and there is no need to say thank you to someone that owes you something. Just my opinion.
Aside from that, the little town of Marion has great potential for being a perfect place in the sun. The weather is mild, the geo-location gives easy access to highways, airports and resort areas.
Conversely, if I were advising a young couple, who planned to have children, or bring children with them, Marion is very disappointing when it comes the education system. We have a child in the 10th grade who is not getting the education he deserves and is affected by the gang activity and general disobedience tolerated by the city, police and school district. It's out of control! If we stay in the community, private school is the only option for the upcoming school year.
There needs to be sweeping reforms in this diamond in the rough. Start with education reform and gang enforcement. These two factors would be the catalyst for change in this community. Better teachers and administrators and enforcement of the law by local law enforcement.
Like when considering relocation anywhere in the country or world, one needs to do a certain amount of homework. There is not Utopia, or perfect place, but there are degrees of good and bad, and I suppose there must be a balance for decent people. I find the balance in Marion is slightly tilting to the overall bad.. but can teter easily to the center or "good" catagory with adjustments.
Hope this helps.

MTwain